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Four barrel carb for 318 #1578715
02/13/14 09:58 PM
02/13/14 09:58 PM
Joined: Nov 2004
Posts: 507
3
340clone Offline OP
mopar
340clone  Offline OP
mopar
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Joined: Nov 2004
Posts: 507
My Challenger has a small block 318 and I am running a '70 340 intake with a '70 AVS Carb. I think it's too much carb for this motor.

Any recommendations on a lesser CFM, AVS style 4bbl carb (Edelbrock) that I could use to tone it down and keep the same look?

Thanks!

Re: Four barrel carb for 318 [Re: 340clone] #1578716
02/13/14 11:33 PM
02/13/14 11:33 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
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Joined: Nov 2003
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Lincoln Nebraska
That ain't too much carb for it. I'm sure it is significantly less than 600 cfm (measure its' bores). What symptoms are you having? I have an Eddy 1406 600 cfm on a DD 318 & it runs flawless. All OE AVS's are emission carbs and are lean plus the air door adjustment. I'd suggest converting to Eddy performer 2 step rods/primary jets from a strip kit with sizes close to whatever is in the AVS right now maybe going several thou smaller on the "cruise" step for a start. You WILL notice the difference but holler back with what's going on


live every 24 hour block of time like it's your last day on earth
Re: Four barrel carb for 318 [Re: RapidRobert] #1578717
02/14/14 01:53 AM
02/14/14 01:53 AM
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dogdays Offline
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When properly adjusted, the air door will make the carburetor only as big as the engine needs.

I am using a Holley Street Avenger 570 on my 318 and it isn't too big. The AVS is most likely smaller, Chrysler didn't put a lot of carb on their regular engines.

R.

Re: Four barrel carb for 318 [Re: 340clone] #1578718
02/14/14 02:02 AM
02/14/14 02:02 AM
Joined: Feb 2004
Posts: 4,501
Gainesville,FL
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goldmember Offline
master
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Gainesville,FL
Quote:

My Challenger has a small block 318 and I am running a '70 340 intake with a '70 AVS Carb. I think it's too much carb for this motor.

Any recommendations on a lesser CFM, AVS style 4bbl carb (Edelbrock) that I could use to tone it down and keep the same look?

Thanks!


It's not that the carb is too big(LOL)it's the tune.

Last edited by goldmember; 02/14/14 02:03 AM.
Re: Four barrel carb for 318 [Re: 340clone] #1578719
02/14/14 03:01 AM
02/14/14 03:01 AM
Joined: Nov 2004
Posts: 507
3
340clone Offline OP
mopar
340clone  Offline OP
mopar
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Posts: 507
The issue I'm having is that it seems to be running too rich. Even when I think it's properly tuned, It's still has a bit of a gassy smell to the exhaust, enough to make your clothes reek! LOL. Engine only has about 500 miles on it. A friend of mine said it was that the carb was too much for the engine. I didn't see how either, but I've adjusted the heck out of it with no real luck...

Last edited by 340clone; 02/14/14 03:03 AM.
Re: Four barrel carb for 318 [Re: 340clone] #1578720
02/14/14 03:09 AM
02/14/14 03:09 AM
Joined: Jan 2005
Posts: 3,344
Central TX
roe Offline
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roe  Offline
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Central TX
Be careful, running excessively lean will give you the same smell of fumes. That's what happened to me, and leaning it out to fix th "Rich" running, fume smelling condition only made it worst.



1971 Plymouth Satellite
408/904 8 3/4 3.23 SG
Re: Four barrel carb for 318 [Re: 340clone] #1578721
02/14/14 03:10 AM
02/14/14 03:10 AM
Joined: Nov 2004
Posts: 2,495
Oregon City, OR
Baxter61 Offline
top fuel
Baxter61  Offline
top fuel

Joined: Nov 2004
Posts: 2,495
Oregon City, OR
I ran a holley 3310 with a pro form main body on a 7.5:1 318 with 360 heads and an air gap intake. It would roast the tires from a slow roll, ran good when rpm'ing, and got 20+ mpg. The carb aint too big, to reiterate from whats been said it just needs to be tuned, those carbs dont flow what thartre "rated" at

Re: Four barrel carb for 318 [Re: Baxter61] #1578722
02/14/14 08:57 AM
02/14/14 08:57 AM
Joined: Jan 2003
Posts: 20,158
Park Forest, IL
slantzilla Offline
Too Many Posts
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Park Forest, IL
I would be more concerned about the port mismatch/vacuum leaks.


"Everybody funny, now you funny too."
Re: Four barrel carb for 318 *DELETED* [Re: slantzilla] #1578723
02/14/14 09:44 AM
02/14/14 09:44 AM
Joined: Sep 2007
Posts: 14,889
up yours
Supercuda Offline
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Supercuda  Offline
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Joined: Sep 2007
Posts: 14,889
up yours
Port mismatch?

Right, keep believing that one

Last edited by Supercuda; 02/15/14 11:58 AM.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
Re: Four barrel carb for 318 [Re: Supercuda] #1578724
02/14/14 12:55 PM
02/14/14 12:55 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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RapidRobert Offline
Circle Track
RapidRobert  Offline
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
I would check the float levels/float saturation/float linkage/needle condition as it might be a carb rich issue. What adjustments have you done? do the boosters drip at idle? As said a lean misfire can kick up the same symptoms as the unburned mixture just goes out the tailpipe where you smell it just like you would smell it if it was excessively rich from a carb issue. regarding a vac leak, how does it run/is there any hesitation anywhere?


live every 24 hour block of time like it's your last day on earth
Re: Four barrel carb for 318 [Re: RapidRobert] #1578725
02/15/14 11:51 AM
02/15/14 11:51 AM
Joined: Nov 2004
Posts: 6,653
Near Reading PA USA
pinkduster Offline
master
pinkduster  Offline
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Joined: Nov 2004
Posts: 6,653
Near Reading PA USA
Back in the late 80s and 90s when we were all driving 318s (old style too) we used to just use the Holley 600 with vacuum secondaries. No problems. Great carbs right out of the box. I've been wanting to put one on my 69 Charger, just hasn't happened yet.







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